I find social events to be like an interactive play. If I choose to participate it will be that much more interesting, but if I don't, and simply watch the evening can still be very entertaining without my active involvement.

So with that notion in mind. Interact with those that interest you, and give simple declining replies to those who approach you that you have no interest in.

Let me give you an example:

I attended our local group munch pretty regularly and became a regular fixture there, though not actively involved in what was presented. People of course knew me, but didn't invite me to the after parties, or to show anyone how to do anything. I was fine with that, I enjoyed talking with them, and leaving when the time came.

At some point one of the submissive women there who needs everyones approval, and is an exhibitionist, noted that I would give disapproving looks to things she would do. I would never say anything, as that wasn't my place. I wasn't her Dom or Master so I shouldn't. I knew this, and respected those boundaries. Well one day she approaches me, and lets me know she thinks I tell things how I see them, and I acknowledge that was a true statement. She asked me what I thought of her. I of course told her, and she asked me to correct her when I thought she needed it. I declined of course, as it wasn't my place to do that kind of thing. She had a Dominant/Master and I told her that the protocol of such a relationship meant it wasn't my place to do that kind of thing. In the end she had her feelings hurt, but I didn't have to worry if I was over stepping any boundaries, both for myself as well as for their relationship.

In short, I was declining a person who wanted some sort of interaction from me. I wasn't willing, and said as much. People don't always like brutal honesty, but when they get it, they respect you for it.

Since your goals in the community are not to become connected, and get some sort of position of authority or prominence. Being brutally honest is not going to cost you anything.